Vesicular transport is Saccharomyces cerevisiae is the interest of our lab. Previously, we identified a gene, SCD5, which encodes a novel protein with a post-Golgi secretory function. Little is known about the exact function of Scd5p. My research objectives are to further define the role of Scd5p in the secretory and endocytic pathways and to identify proteins that function in the same pathway as Scd5p using genetic approaches. A pseudoreversion screen using scd5-delta338, a temperature sensitive (ts) allele of SCD5, will be used to find gene products that interact genetically with Scd5p. In addition, a multicopy suppressor screen will be utilized as a secondary screen to identify proteins that interact with Scd5p or fulfill a similar function as Scd5p. After the isolation and cloning of the suppressors, gene disruptions will be analyzed for null phenotypes. Ultimately, mutant alleles of the suppressors will be tested for their effects on secretion, endocytosis, cell polarity, and cell morphology, which should assist in clarifying Scd5p's purpose within the cell.